Rotary gripping device



June 26, 1962 T. RAUH ROTARY GRIPPING DEVICE 2 Sheets-Sheet 1 Filed Dec. 11. 1959 Z4 5 Z 3 7 3 G 7 no I [Z A I p Z? w 2 I F a n 42 Z w W54 W J INVENTOR. THO/144$ M 40 4770NEY 1 June 26, 1962 T. M. RAUH ROTARY GRIPPING DEVICE 2 Sheets-Sheet 2 Filed Dec. 11, 1959 FIG. 50

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United States Patent 3,040,854 ROTARY GRIIPING DEVICE Thomas M. Rauh, Calumet City, Ill. (3560 South County Road, Palm Beach, Fla.) Filed Dec. 11, 1959, Ser. No. 859,015 3 Claims. ((11. 192--45.1)

This invention relates to improvements in rotary gripping devices, such as clutches, wherein an expanding rotor is engaged in a tubular stator.

The primary object of the invention is the provision of a simpler and more effective and efiicient device of the kind indicated, which is composed of a small number of uncomplicated and easily assembled parts, and wherein the jaws of the rotor are expanded and contracted with out the use of springs and without making contacts with each other, and are tightened in expanded stator-gripping positions, by cam action of a rotary expander.

Another object of the invention is to provide a device of the character indicated above which is especially useful for providing such as small internal combustion engines with mechanical starting means, through the use of an attached electric motor or unmounted application of an electric hand drill or the like.

Other important objects and advantageous features of the invention will be apparent from the following description and the accompanying drawings, wherein, for purposes of illustration only, a specific form of the invention is set forth in detail.

In the drawings:

FIGURE 1 is an exploded fragmentary side elevation, showing a device of the invention, including a drillchucked rotor and an engine shaft mounted stator, with the rotor removed from the stator;

FIGURE 2 is a transverse section taken on the line 2-2 of FIGURE 1, showing jaws in expanded and in gripping positions;

FIGURE 3 is an enlarged fragmentary longitudinal section taken on the line 33 of FIGURE 1;

FIGURE 4 is a view like FIGURE 2, showing the jaws in similar but reversed positions;

FIGURE 5 is a group side elevation showing the parts of the rotor separated;

FIGURE 6 is an exploded face view showing the jaws absent from FIGURE 5;

FIGURE 7 is a fragmentary side elevation, on the scale of FIGURE 3, of the stator, showing its parts separated; and,

FIGURE 8 is an open end elevation of another form of stator.

Referring in detail to the drawings, wherein like and related numerals designate like and related parts throughout the several views, and first to FIGURES 1 to 7, the illustrated device, generally designated 10, comprises a hollow tubular stator 12, to be fixed on work or an object to be turned, such as the shaft 14 of a small internal combustion engine E; and an expandible and contractible rotor 16, to be engaged in the stator 12, and which is to be fixed on a power driven turning element, such as the shaft of an electric motor, which can be the shaft 18 of a portable electric drill, having a chuck 19 receiving the rotor 16.

The stator 12 is preferably cup-shaped, as shown and involves a plain cylindrical side wall 20, a closed end Wall 22, opposed to the open end 24 of the stator, and means on the end wall 22 for mounting on the engine shaft 14, such as an axial opening 26 through which a reduced threaded stud 23 on the shaft 14 extends, a washer 36 and a nut 32 being tightened on the stud 28 against the inside of the end wall 22 in opposition to a shoulder 34 on the shaft 14. A keyway '33 in the stud 28 accommodates a key 35 on the stator.

3,646,854 Patented June 26 1962 ice In the form of the invention shown in FIGURES 1 to 7, the stator side wall 20 is smooth, so as to provide for a certain amount of slip between the stator 12 and the rotor 16, available in case of back-fire of the engine E, to prevent damage to the components. In the form of stator of the invention shown in FIGURE 8, and generally designated 12a, the sidewall 22a is modified, and is mutilated to provide circumferentially spaced ramps 36 and ratchet notches 38, to be engaged by rotor aws, to preclude slippage of the rotor in the stator, in one direction.

The rotor 16 further comprises a bit 40 having on one end a reduced axial spindle 42, to fit in the hand clutch 19 of the drill shaft 18. The bit 40 tapers in a direction away from the tang 42 and terminates in a squared fiat end 44, in which is provided a threaded axial socket 46, to receive an assembling screw 48 having a tapered head 50.

The rotor 16 further comprises a hub 52 having a tapcred bore 54 therethrough which removably receives the bit 40 and is held thereon in a jam fit, by engagement of the tapered head 50 of the screw 48 in the related end of an opening 56 in a disc 58, which is larger in diameter than the end 44 of the bit, and engages the related end of the hub. The hub has a lateral annular flange 60 located between and spaced from its ends, which defines grooves 62 and 64 at opposite sides thereof, in which circular outer and inner discs or plates 66 and 68, respectively, are rotatably confined.

The outer disc 66 is larger in diameter than the stator 12 so that, when the rotor 16 is engaged in the stator 12, the outer disc makes frictional stop engagement with the open end 24 of the stator. The inner disc 68 is smaller in diameter than the outer disc 66, and is small enough in diameter to be freely insertable and removable from the stator 12. i

The hub flange 60 is a hexagonal cam and is provided with a plurality of similar flat chordal cam faces 70, six in number for operating the three jaws illustrated. The cam faces 76 are similar in length, are symmetrically related to the center of the cam, and intersect at related ends, to define corners 72.

Three jaws are journalled on and between the discs 66 and 68, at equally circumferentially spaced. intervals,

on similar pins 76, which comprise large diameter central journal portions 78 and reduced diameter end portions 80 and 82, which are inserted in related openings 84 and 86, respectively, which are provided in the discs 66 and 68, the central portions '78 serving to space the discs 66 and 68 from each other and to provide mutual support there between. The discs 66 and 68 and the pins 76 are assembled in clamped relationship to each other by suitable means, such as studs threaded in sockets in the outer ends of the pin end portions 80 and 82, having enlarged heads 92 which bear against the related sides of the discs.

The expanding jaws comprise jaws 94- and 96 and an intervening jaw 95, which are flat plates of a. thickness to occupy the space between the discs 66 and 68. The jaws 94 and 96 are similarly shaped, but are reversed and inverted with respect to each other, and the intervening jaw 95 has another shape.

The jaws 94 and 96 are chordally elongated with respect to the discs 66 and 6S and have outer longitudinal edges which include curved stator gripping portions 98, of a curvature substantially that of the stator side wall 20, and straight retreatantly angled edges 1% which avoid contact with the side wall 20. These jaws have substantially parallel end edges 102 and 104 which are angled relative to the longitudinal axes of the jaws, and pin-receiving holes 106 are formed in the jaws and are displaced slightly toward the end edges 194, shown in FIGURES 2 and 4.

The jaws 94 and 96 have inwardly projecting heels 108 on their inward longitudinal edges, which are located between the pin holes 106 and the end edges 104, the heels being segmental in shape. On the inward longitudinal edges of the jaws 94 and 6 and extending from the heels 108 to the end edges 102, are longitudinally bowed cam edges 110, with which the corners 72; of the cam 60 are engageable, as shown in FIGURE 2, to expand the jaws. The heels 108 have corners 112 facing the cam edges 110, for engagement by the edges 70 of the cam 60 to swing the jaws, in a releasing action, away from the stator side wall 20, and lock them in these positions, as shown in FIGURE 2.

The intervening or intermediate jaw 95, which is disposed opposite to and between the jaws 94 and 96, has a chordally elongated shape, but is devoid of a heel, and its inward longitudinal edge is composed of a relatively long straight portion 114 and a relatively short straight portion 116, which are angled with respect to each other and intersect at their inner ends in a nose 118. As shown in FIGURE 2, the long inward edge portion 114 faces a stop pin 120 which is suitably fixed to the discs 66 and 68 and extends alongside of the cam 60 and between a related face 70 thereof and the long edge portion 114 of the intermediate jaw 95. The stop pin 120 is spaced radially from the cam at no greater distance than to enable a related cam face 70 to be out of contact with the pin 120, except when the cam is rotated, in opposite directions, to put a cam corner 72 in contact with the pin 120. This arrangement leaves the cam 60 free to cam the jaws from retracted positions to expanded stator gripping positions, in one direction of rotation, while in effect limiting rotation of the cam in the opposite direction in order to prevent locking of the jaws by the cam, which might otherwise occur.

With the arrangement and disposition of the jaws, as illustrated in FIGURE 2, driven rotation of the bit 40, and hence of the cam 60, in a clockwise direction, produces outwardly swinging expansion of the jaws into gripping engagement with the inside of the stator side wall 20. When the motor E has become started and its shaft turns faster than the cam 60, so that the stator 12 overruns the rotor 16, the cam 60 in effect stops relative to the stator 12, so that the cam corners 72 which were camrned against the heel corners 112 and against the cam edges 110 of the jaws 94 and 96, and the cam corner 72 which was cammed against the edges 1'18 of the jaw 95, are partially retracted radially inwardly, so that the jaws can swing away from and out of gripping relation to the stator side wall 20. FIGURE 4 shows a reversed arrangement of the jaws for expansion and contraction thereof by relative rotations of the rotor and stator opposite to those outlined above.

It is obvious that the rotor 16 can be permanently mounted within the stator and driven by a stationary motor installed on the engine E, instead of being separably mounted on the shaft of a portable drill.

While there have been shown and described herein preferred forms of the invention, it is to be understood that the invention is not necessarily confined thereto, and that any change or changes in the structure of and in the relative arrangements of components thereof are contemplated as being within the scope of the invention as defined by the claims appended hereto.

What is claimed is:

1. A rotary gripping device comprising a tubular stator for securement on an object to be rotated, said stator having a cylindrical side wall, a rotor for securement on a driven rotary element, said rotor being engageable endwise within the stator, circumferentially spaced pivoted jaws on the stator having stator side wall gripping edges and cam edges opposed to the gripping edges, a hexagonal cam disposed centrally with respect to said jaws and fixed relative to said rotor, said rotor having a hub, support means journalled on said hub and freely rotatable relative to the hub on which the jaws are pivoted, said cam having circumferentially disposed edges and corners between these edges, the corners being arranged to engage the cam edges of related jaws, and means for holding said support means stationary relative to the rotor, said hub having outer and inner peripheral grooves, said support means comprising outer and inner discs rotatably circumposed on the hub and severally confined in the outer and inner grooves, said jaws being positioned between the outer and inner discs, with the gripping edges of the jaws extended beyond the edge of said inner disc in the expanded condition of the jaws, said holding means comprising peripheral portions on the first disc held in engagement with the stator side Wall.

2. A rotary gripping device having a stator adapted to be fixed to an object to the rotated and a rotor adapted to be fixed to a driven rotary element, said stator being annular and having a side wall within which the rotor is rotatably engaged, said rotor having circumferentially spaced jaws pivoted thereon, said jaws having outer stator side wall engaging edges, and inner cam edges, said jaws comprising a pair of main jaws and a single jaw located between the main jaws and located on the opposite sides of the rotor from the main jaws, said main jaws having inwardly extending lateral heels at one end of their cam edges, said heels having corners, said rotor comprising a hexagonal cam centered relative to the jaws, said cam having flat edges intersecting in corners, said corners being located intermediate the ends of the jaws, the single jaw having a corner intermediate the ends of its cam edge, the cam being adapted to be rotated in one direction to engage a corner thereof with the cam edges of the main jaws and pivot the main jaws into gripping engagement with the stator side wall, with an edge of the cam engaged with the corners of the heels so as to lock the main jaws in gripping positions, and with a corner of the cam engaged with the corner of the single jaw, and stop means on a main jaw positioned to be engaged by an edge of the cam.

3. A rotary gripping device having a stator adapted to be fixed to an object to be rotated and a rotor adapted to be fixed to a driven rotary element, said stator being annular and having a side wall within which the rotor is rotatably engaged, said rotor having circumferentially spaced jaws pivoted thereon, sai-d jaws having outer stator side wall engaging edges, and inner cam edges, said jaws comprising a pair of main jaws and a single jaw located between the main jaws and located on the opposite sides of. the rotor from the main jaws, said main jaws having inwardly extending lateral heels at one end of their cam edges, said heels having corners, said rotor comprising a hexagonal cam centered relative to the jaws, said cam having fiat edges and corners located between adjacent edges, the single jaw having a corner intermediate the ends of its cam edge, the cam being adapted to be rotated in one direction to engage a corner thereof with the cam edges of the main jaws and pivot the main jaws into gripping engagement with the stator side wall, with an edge of the cam engaged with the corners of the heels so as to lock the main jaws in gripping positions, and with a corner of the cam engaged with the corner of the single jaw, a stop pin on the stator located between a main jaw and said single jaw, and a pin on a main jaw positioned to be engaged by an edge of the cam as the cam is rotated in the opposite direction.

References Cited in the file of this patent UNITED STATES PATENTS 1,773,120 Richter Aug. 19, '1930 1,861,486 Tromanhauser June 7, 1932 2,868,186 Schnacke Jan. 13, 1959 FOREIGN PATENTS 715,604 France Sept. 28, 1931 150,009 Australia Feb. 12, 1953 

